Also, neither Crohnâs disease nor ulcerative colitis is related to food allergies. According to the Crohnâs & Colitis Foundation of America: âPeople with IBD may think they are allergic to foods because they associate the symptoms of IBD with eating.â.
Eczema, also known as dermatitis, describes a group of skin conditions where the skin is irritated or inflamed. There are many different types of eczema - the most common is atopic eczema (also called endogenous eczema). About 1 in 6 children get atopic eczema in the UK, but most grow out of it by their teens.
1 But sarcoidosis can also show up suddenly with the appearance of skin rashes.  Tender, raised, red bumps (called subcutaneous sarcoidosis or erythema nodosum) on the shins of the legs, or less frequently on the arms, are common and can cause leg or arm pain.